Down Payment Calculator

Loan = price − down payment; LTV = loan ÷ price. PMI applies whenever LTV is above 80% (down payment under 20%) and drops off once the balance reaches 80% of value. More down means a smaller loan, a lower payment, no PMI past 20%, and less total interest.

The 20% threshold is the decision point

Every percentage point of down payment ripples through the whole loan: a bigger down payment means a smaller loan, a lower monthly payment, and less interest paid over the years. But one point matters more than all the others — 20%. At or above 20% down (a loan-to-value ratio of 80% or less), there is no private mortgage insurance. Below it, the lender adds PMI to every payment until your equity climbs back to 20%. That makes the jump from 19% to 20% worth far more than the jump from 9% to 10%, and it is why this calculator puts the LTV and the PMI status front and centre.

The calculator shows your loan, payment, LTV and PMI at the down payment you enter, and — if you are below 20% — exactly how much more you would need to put down to avoid PMI, and the total PMI you would otherwise pay before it drops off. That last figure is the real, often-overlooked cost of a smaller down payment.

Worked example — a $400,000 home at 6.5% over 30 years: Put 10% down ($40,000) and the loan is $360,000 with about $180/month of PMI and a $2,972 payment. Put 20% down ($80,000) and PMI disappears, dropping the payment to about $2,539. The extra $40,000 down also saves roughly $17,000 of PMI and $51,000 of interest over the loan.

Compare the levels — the table is the point

There is no single right down payment, so the calculator lays out the common choices — 5%, 10%, 15% and 20% (plus your own) — side by side. For each it shows the down amount, the loan, the monthly payment, the PMI and the total interest, so you can see the trade-off whole rather than guessing. The pattern is consistent: each step up lowers the payment and the interest, and the step to 20% does something the others cannot — it removes PMI entirely, which is the visible cliff in the chart of payment against down payment.

Use it to weigh the upfront cash against the ongoing cost. A larger down payment ties up money you might want for renovations or an emergency fund, so it is not automatically right — but the comparison makes the cost of a smaller one explicit, rather than hidden in a slightly higher payment.

Cash at closing, and saving toward the goal

The down payment is not the only cash you need on the day. Closing costs — typically 2–5% of the price — are paid on top, so the calculator adds them to give the total cash needed at closing. It is a number worth knowing early, because it is often thousands more than buyers expect and it competes with the down payment for the same savings.

If you are still saving, switch on the savings-goal fields: enter how much you set aside each month and what you have saved already, and the calculator works out how long until you reach the down payment. It turns an abstract target into a timeline — and shows how aiming for 20% rather than 10% changes both the wait and the lifetime cost.